Backfiring like crazy

[jellywrestler]

Used to go down the Grafton offramp toward Wellesley Street, hit the kill switch while at a good speed, pause, then turn it back on again.

Man, backfire...........you have no idea. Cleared the senses, I can tell ya.

and you're now a policeman? How did you get a badge with a background like that?

[Phantom Limb]

Learn to love it.
Coming down the valley into my home town my 1300 sounds like rolling thunder. Makes a great warning device for coming up behind slower riders, they definitely know somethings coming

[rastuscat]

and you're now a policeman? How did you get a badge with a background like that?

I proved I was human. That used to count for something.

[skippa1]

I proved I was human. That used to count for something.

Not now. Even my phone is an Android

[Tunahunter]

My bike's Two Brothers pipe makes a really good backfiring (type) noise, I love it and so do the punters walking over the motorway overbridge on Hill Street Wgtn when I'm decelerating heavily after a big burst out of The Terrace Tunnel

[Fast Eddie]

Used to go down the Grafton offramp toward Wellesley Street, hit the kill switch while at a good speed, pause, then turn it back on again.

Man, backfire...........you have no idea. Cleared the senses, I can tell ya.

hahaha..

you do it on the work bike?

[rastuscat]

hahaha..

you do it on the work bike?

I am stupid at times,but not THAT stupid.........

[Oakie]

I am stupid at times,but not THAT stupid.........

Hey RC, you guys have ID numbers or something on your helmets? I followed a couple of cars behind a two wheeled popo for a bit yesterday morning and he seemed to have what looked like a number '3' on the back of his lid?

[rastuscat]

Hey RC, you guys have ID numbers or something on your helmets? I followed a couple of cars behind a two wheeled popo for a bit yesterday morning and he seemed to have what looked like a number '3' on the back of his lid?

Well spotted.

We recently put numbers on the rear of our helmets for a motorcade operation. It was a very highly ranked overseas visitor. Our motorcade commander complained that he couldn't tell the difference between us from behind, so we put big numbers on the back of our helmets.

Mines the exception. I just got a new helmet, so no number. I was on one bike yesterday, the other bike rider was another full time rider who was working. He has the 3.

We are quite different to the educated eye, but to many we all look alike. Yesterday a bloke walked up to me when I was parked doing some paperwork. He told me he had almost flipped me the bird, coz he thought I was one of my other riders, a mate of his. Ya gotta love a sense of humor.

[Oakie]

So if we see a two wheeled popo with no racing number on his lid we can give you the old KB wave?

EDIT. On second thought that won't work as we'll be behind you. I know, we'll just catch up and give you a wave as we overtake ...

[rastuscat]

So if we see a two wheeled popo with no racing number on his lid we can give him the old KB wave?

EDIT. On second thought that won't work as we'll be behind you. I know, we'll just catch up and give you a wave as we overtake ...

Be careful. One of my guys was injured in a crash back in March. He will be back riding in maybe Nov. he wasn't on the numerical motorcade, so his helmet looks identical to mine. System 6 BMW helmets in white.

The stripes are a clue. I wear 3, each of my guys wear 1.

Flip me the bird any old' time. I've got a thick skin!

We change bikes at times too. I normally ride 56 when I'm working, the other is 59.

Stop me for a chat, you might be surprised how much we have in common.

[Oakie]

Stop me for a chat, you might be surprised how much we have in common.

Don't think I'd be surprised at all. I've always got on pretty well with popo. One even offered to take me on patrol one night when I was writing an article for the local newspaper. Fun times. The highlight was him pushing me through a bathroom window to get access into a house when the person renting it for the weekend had not been able to pick up his keys. (Yes we checked it was a kosher rental first).

Thought from time to time about stopping and saying hi to a bike popo but wondered how I'd start that conversation:
"Hi, are you RastusCat?". Do the other bike popo know your alter ego? Could be bad for me if they didn't. Three stripes though. I'll remember that.

[Conquiztador]

Back to the issue.

A few ideas:
- 98 octane is made for high compression engines and will burn slower than 91 octane (98 octane has stuff added so it does not burn too fast). There is a possibility that if you use 98 octane the fuel does not have time to burn.
- A leak in exhaust (small hole or poorly connected header pipes) can allow air (and therefore oxygen) in to the exhaust allowing for any unburnt fuel to be ignited by hot header pipes and therefore causing the backfire.
- Exhaust valve leak (caused by seat wear or cam timing issues) could also allow fuel in to the headers.
- Crappy spark plugs maybe?
- And ignition timing (too late) might also cause unburnt fuel to get in to headers?

All this is based on carbi engines so might not be directly relevant to EFI ones?

I agree with a earlier poster: Take her in to get new plugs and tuned and I suspect you will have it all sorted.

Good Luck!

[rastuscat]

Back to the issue.

A few ideas:
- 98 octane is made for high compression engines and will burn slower than 91 octane (98 octane has stuff added so it does not burn too fast). There is a possibility that if you use 98 octane the fuel does not have time to burn.
- A leak in exhaust (small hole or poorly connected header pipes) can allow air (and therefore oxygen) in to the exhaust allowing for any unburnt fuel to be ignited by hot header pipes and therefore causing the backfire.
- Exhaust valve leak (caused by seat wear or cam timing issues) could also allow fuel in to the headers.
- Crappy spark plugs maybe?
- And ignition timing (too late) might also cause unburnt fuel to get in to headers?

All this is based on carbi engines so might not be directly relevant to EFI ones?

I agree with a earlier poster: Take her in to get new plugs and tuned and I suspect you will have it all sorted.

Good Luck!

Well informative post.

Is it the same with the V8 super cars? They spew flames out on deceleration, and they are surely fuel injected. Guessing they don't burn all the fuel that gets pumped into the system, and that the exhaust gas is so hot it ignites on the way out.

Ta for getting us back on track.